A cobpobation op new jebsey



Nov. 13, 1928.

C. A. A. RAND FEEDING MEANS FOR CENTRIFUGAL GRINDERS Filed Dec. 17, 192311 51 9* 1 zg/fifi a a 1A E J 1/7, It I 57% J7 10 1,2 3% Z9 PatentedNov. 13, 1928 UNITED STATES PATENT OFFICE.

CHARLES A. RAND, OF CHICAGO, ILLI NOIS, ASSIGNOR TO INTERNATIONAL HAR-VESTER COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF NEW JERSEY.

FEEDING S FOR CENTRIFUGAL CBINDERS.

Application filed December The present invention relates to improvementsin centrifugal grinders and has for its object to improve the efliciencyof such machines, and more particularly of the feedmg means employedtherewit In the type of centrifugal grinders lmown as rotary hammermills, the reduction of grain, forage, etc is effected by pivotedhammers carried on a rotor which revolves at high speed above aperforated metal screen curved to conform to the circuit described bythe hammers during rotation. The ground material is preferablydischarged or drawn 0E and collected by a current of air drawn throughthe mill, and it is the object of this invention to-insure entrance ofthe required supply of air to the grinding chamber and to make theentering aircurrent take the path of the material being fed into the'mill so that feeding is facilitated and there is no tendency for thematerial to choke or be thrown back.

A further object of the invention is to provide feeding means includinga chute and an adjustable inlet gate or plate which afford a feedopening or throat that may be varied in size by adjusting the gate andto conduct the inflowing air by means of a conduit or duct on the gateto an opening or air port in the gate just above the feed throat and,therefore, always in the same relation to the material being fed,irrespective of the adjustment of the inlet gate;

With these main objects in view, the invention resides in thecombination and arrangement of parts and details ofconstruction, or theequivalents thereof, hereinafter more articularly describedand claimed.

Re erring to the accompanying draw- Tig. 1 is a plan view of a grinderwith the novel feeding device attached;

Fig. 2 is a similar side view; and Fig. 3 is a detailed view of theinner side of the inlet'plate or gate. The-grinder with which theinvention is combined may be of anypreferred construction, and, in thisinstance, there is illustrated a grinder comprising a casing formed of aa lower fixed section 10 and an upper section or dome 11 which is hin edto the lower section at 12 and is detachalily secured thereto as by apivoted bolt 13. The lower sec- I 'tionlO is composed of similar endplates which support the sheet metal hopper or bin 17, 1923. Serial No.681,073.

the discharge spout 16 by means of an ex- The upper haust fan in theusual manner. section 11 is also composed of similar end plates whichmay beof cast metal and these are connected by a rear curved sheet metalplate secured to the end plates in any suitable way, and reinforced by aseries of transverse rods 17 connecting the edges of the end plates; Thelower part of the front of the upper section of the grinder casing isalso formed by a curved plate reinforced by rods similar to those abovedescribed, and the relative curvatures of the front and rear plates ofthe grinder are such that their upper ends are spaced apart verticallyleaving a feed inlet which is, in general, tangentially related to therotor within the casing. The rotor, which is shown in dotted lines inFig. 2, is carried on a shaft 18 journaled in split bearings 19 formedin the respective edges of the upper and lower side plates 10 and 11.A'driving pulley. 20 is provided on the projecting end of lthe rotorshaft 18.

a The grinder construction just described forms no part of the presentinvention except as it cooperates therewith, and the parts more directlyrelated to the invention comprise a feed chute or conveyor 21in the formof an open trough which is pivotally connected at 22-at the lower'edgeof the feed inlet of the grinder and extends therefrom in a generallyHorizontal direction. At the.

tends downwardly at an outward angle to a point adjacent the floor ofthe chute 21.

Chute 21 is adjustably supported by brace bars 24: which, together withbars25 engaging the sides of the chute, are attached at 26 to ears orlugs on the bottom of the chute 21.

The lower edge of the inlet gate 23 is supported by slotted arms 27 theupper portions of which are adjustable between clamp collars on atransverse rod 28 extending across the chute and connecting the upperends of the bars 25. WVing nuts 29 are pivoted on the ends of rod 28 forclamping the supporting bars 27 at any desired adjustment. This providesmeans for adjusting the inlet gate onits pivot and varying the size ofthe feed aperture or throatallowed between the lower edge of the gateand the bottom of the feed chute, as required for the particularmaterial being fed to the grinder; It will be evident that thisconstruction permits variation of the feeding opening as desired andthat the unused area of the grinder inlet is always closed by the ate 23and dust, etc., thereby confined. Astlie feeding throat allowed by thegate is usually closed by the,

The slot 30 opens into or communicateswith T an 'air duct or conduit onthe outer face of the late 23 and formed by a casing 31 se cure thereon.The conduit 31 opensnear the upper ed e of the plate at 31 where the airenters an is directed downwardly to the opening-or slot 30, throughwhich it passes;

enterin directly above and being directed in the pat ofthe materialbeing fed just be neath the lower edge of gate 23. In this manner theblast of entering air is caused to flow in the direction of travel ofthe material and assists the feeding operation as well as supplying thenecessary amount of air to the grinderr It will be noticed thatarrangement of the air port is such that it remains 1n practically thesame relation to the material at all adjustments of the plate 23 andthat the arrangementof the chute 21 and vented.

While the construction'above described'ex-, '45

plate or gate. 23 with'relation to the inlet opening of the mill is suchthat escape of dust andsuch material as may be thrown back from therotor will be effectively preemplifies the preferred form of .theinvention, it is obvious that certain changes in details of constructionmay be made without departin from the scope of the invention as definein the following claims.

What is claimed is: i I

1. Animprovement in centrifugal grinders comprising a'casing having alateral feed opening, a trough shaped chute extending substantiallyhorizontally from said casing for guiding materialto said lateral feed'cpenl'ng, a gate pivotally mounted'so as to extend within the saidchute downwardly and outwardly with respect to said casing, the gatehaving an air port formed therein, a shield covering the port, and meansfor 'adjustably supporting the gate.

2. An improvement in centrifugal grind- .ers comprising a casing havinga lateral feed opening near (the top thereof, a trough shaped chuteextending substantially horiing near its lower edge.

zontally from the top of the casing so as to guide material to thelateral feedopening, agatepivotally mounted with respect to the top ofthe casing and extending outwardly and downwardly therefrom within thechute, the gate being so positioned that its lower edge is adjacent thefloor of the chute, a

casing secured to the gate so as tooform an air passage therewith, andmeans for supporting the gate withln the chute including means foradjusting the gate on its pivot.

3. The combination with a grinder casing having a lateral feed opening,of a troughv having a lateral feed opening, of a trough shaped chuteextending therefrom and a v gate for said opening consi'sting of a plateadjustably pivoted at the upper edge of the opening and extending at anoutward angle to a point adjacent the floor of the chute, said platebeing provided Wlthfi-Il air open- 5 The combination with a grindercasing having a lateral feed opening, of a trough shaped chute extendingtherefrom, a gate its outer side extending from a 4. The combinationwith agrinder casing I for said opening consisting of a plate pivoted'at the upper edge of said opening and extending at an outward angle to apoint adjacent the floor of the chute, said plate having a transverseslot near its lower edge and being provided with an air conduit on itsouter side extending from a higher point onthe plate down to said slot,and adjustable supporting means connected to the lower part ofthe-plate.

6. The combination witha material treating device having pneumaticdischargingmeans, a chute of feeding means comprising an adjustable gatehinged at the inlet of the device, and means for supporting thegate sothat it extends downwardly within the chute, said gate being providedwith a hood ed air inlet port at a point adjacent the feed openingallowed beneath the lower edge of the gate;

7. An improvement chines comprising, in combination, a material treatingdevice, a casing substantially comminuting maenclosing said device," achute for directing material toward the device, an adjustable gatemounted iii-the chute in' proximity to the inlet of the casing forpreventing the escape of material which has been acted upon by thedevice, the gate being formed with an air port for allowingthe passageof airthrough the machine along with the material acted upon, and ashield covering Leena the port and preventing the passage of material tobe comminuted throughthe port.

8. An improvement in a feeding device for a mill comprising, incombination, ma-

5 terial directing means for guiding'material toward the mill, a movablegate in said means and located adjacent the mill for preventing theescape offmaterial which has been acted upon by the mill, said gatebeing 10 formed with a port allowing the passage of air through the millalong with the material acted upon by the mill, and a member secured tothe gate so-as to cover said port and prevent the passage of materialthrough the port toward the mill, said member being spaced from the gateand forming an air passage-way between itself and the gate.

In testimony whereof I affix my signature.

CHARLES A. A. RAND.

